The Analysis And Spectrum Simulation Of Alexandrium Tamarense Optical Properties

Red tide is a serious marine disasters, which endangers aquaculture and fishing, destructs marine environment, affects the marine tourism and threatens the marine food security. Hyperspectral remote sensing to monitor red tide has advantage of real time or near real time, imaging and comparative cheapness, especially has broad prospects in the optical properties of red tide water. The algae in water as the main component of the red tide has a very complex physical process of interaction with light, but the domestic and international research in this area is relatively scarce. Therefore, to carry out the optical properties analysis of algae and the simulation of electromagnetic scattering model, help better grasp the occurrence and changes in mechanism of red tide, provide technical support for monitor and analysis of red tide, as well as identification of the dominant species of algae. This thesis is on the basis of National Natural Science Fund "the spectral simulation of typical red-tide algae in our country" carry out firstly laboratory culture of Alexandrium tamarense. Observation and analysis of optical properties and characteristics of spectral simulation study yielded the following results:(1) Spectral observation was shown that:the multiple scattering of light within the instrument channel is an important source of measurement error, This thesis compared the current method and proposed a method of the linear regression measuring absorption value and dilution ratio combined with controlling the scope of the optical thickness which can eliminate measurement error.(2) It was found that chlorophyll a (Chla) concentration and cell number density was shown logarithmic growth with time, but no significant changes in cell size of the law. through observation and analysis of biological parameters.(3) The study of spectral data shows that:absorption spectrum shows bimodal distribution, because of the subsidiary of the pigment, the absorption peak of 440nm is about 2 times of 675 nm, the scattering value was inversely proportional to the value of absorption the law, which provide theory basis for the spectral simulation and remote sensing quantitative retrieval basis.(4) By comparison of the simulation and the measured data, that the uniform sphere model (Mie theory) is fit for the establishment of Alexandrium electromagnetic scattering model. (5) Simulation showed that:(1) volume scattering function changes in the spectrum within 6 orders of magnitude; (2) when the scattering angle is close to 0°, the scattering values may be overestimated (3) the backscattering value is much smaller than the scattering, and backscattering probability is low; (4) 116°of the scattering intensity has good correlation with backscattering; (5) the characteristics reflectance peak of Alexandrium is after 680nm, the different dominant species of algae are significant differences in their spectral characteristicsThrough these work, you can grasp the variation of biological parameters and spectral change mechanism for remote monitoring for red tide control.